Quote improved error handling code, update submodule commit

Apps/Examples/Files/Pictures/Source_Code.rst

@@ -97,7 +97,7 @@ We iterate over the files in the directory, loading each of them at the size req
 .. literalinclude:: app/src/main.py
    :language: python3
    :start-at: os.listdir(pictures_dir)
-   :end-at: self.model.append
+   :end-at: pass
 
 Each thumbnail is added as a list of fields with types that correspond to the ones we specified when we created the `Gtk.ListStore`_ model.
 

app @ f979e426

-Subproject commit 4bb65b4b5bf83530b7ccd64d2a661edf34cc997f
+Subproject commit f979e426740d63548f0929d0fb718fb16d8d527c